Sighting device.



OTTO RITTER VON EBERHARD.

SIGHTING DEVICE.

APPLlcAnoN man umu. 1913.

1,157,468. Patented Oct. 19, 1915.

1000 m /5 20 2.5 as p/550 g@ 90,00

Mij

Y of sight, will hit the target.

l Enron?.

oTTo EITTEE von EBERHAED, or BEEDENEY, NEAEEssENLoN-THE-EUHB., GERMANY, AssIeNon To FRIED. nur? AKTIENGESELLSCHAFT, o E `EssEn-olv-THE-nuem,

GERMANY.

To all 'whom'it may concern.' l Be it known that I, 0Tro RITTER vox- EBERHAED, residing at Bredeney, near Essenon-the-Ruhr, Germany, a subject of the Emperor of Germany, have invented a cer tain new and useful Improvement in Sighting Devices, of whichy the following is a specification.

The presentV invention relates to sightingl devices and Vposition finders for projectile.

ejectors used on air vehicles, especially on flying machines, by means of which it will be' possible, to adjust the angle of ejection corresponding to the air ships height above ground, when this height is known and after deciding the time necessary for traversing the horizontal distance, proportionate to the height, but without previously having to ascertain the speed of flight based on measuring the time by computation orby tables. The expression angle of ejection is then understood to mean, the angle formed between the line of sight and a horizontally or vertically adjustable straight line, which is kept rigid on the sighting device, so that a projectile, which has been thrown at the moment the target passed through the line Sighting devices of the prior art have the disadvantage that the time which is required to traverse a horizontal distance proportionate to the altitude of flight, has again to be found out for every change of altitude of flight.

The obiect of the present invention is now to provide a sighting device of this kind, which is without this disadvantage.

In the accompanying drawings is illustrated one embodiment of the invention, and

Figure l shows a side view of the device partly in section; Fig. 2 a top plan view of Fig. 1; Fig. 3 a section along line 3 3 of Fig. 1, seen from above; Fig. 4 a. section along line 4- 4 of Fig. 2, seen from the .left and on larger scale and Fig. 5 a development of the cylindrical surface of a detail of cylindrical shape.

Arbracket A, for carrying the sighting device is rigidly connected with a part B of the air ship. On the bracket A is provided a vertical trunnion a1, upon which is journaled a hood C, with a stop-watch o1. Be-

tween the hood C and the trunnion a1 is insorted a self-locking worm gear, the .worm

i D of which with a handwheel d1 runsin Specification of Letters Patent.

SIGHTING DEVICE.

Application led ,December 17, 1913. Serial No. 807,306.

worm teeth a2 of the trunnion a1, see Figs.v

l and 3. A Vfork having two prongs E and El, is loosely mounted to oscillate on the hood C, by means of a journal e2, the axis of which intersects the axis of the trunnion al at right angles. A shaft F provided with a small hand-wheel f1 and arranged at right angles to the journal e2 is mounted in bearings in the fork prongs E and El, between which a sleeve G is revolubly mounted on the shaft F. The sleeve G has a circular cut g1, see Fig. 1, the axis of its curvature being parallel with the axis of the shaft F. In this cut is guided a sight bar H, which is correspondingly curved along a portion of Vvits length, and provided with a point h1 and a notch h3 in a transversely adjustable slide k2. The circularly curved portion of the sight bar has teeth which are in mesh with a pinion f2 rigidly secured on the shaft F. A counterpoise G3 is suspended from the sleeve G Yby means of a rod g2, which is rigidly connected therewith, and this counter-poise is able to retain the sleeve G, inde-A pendent of the adjustment givenA the sight bar H by the gearing f1 F f2 z.4 during the swaying'of the ying machine, in such a position, that the axis of vthe rod g2 stands vertical.

A drum J, having two sets of curve lines 'il and 2 scribed on its cylindrical surface is pushed over a portion f3 having sguare cross section, of the shaft F, extending beyond the fork-arm E1. The drum is at its end faces held by two arms K and K1, mounted on the shaft F connected by a cross piece k2,

of which arms the one K is rigidly connected with the prong E1. On the arms K and K1 relative to which the shaft F may be freely turned, is revolubly mounted a screw-spindle M provided with a small hand-wheel m1 and by 'means of which a slide N may be axially displaced along the cross piece k2. Y, On the slide N is arranged an index nl for the curve lines il and 2. To read the axial adjustment of the in dex nl, corresponding to the altitude of flight of the air ship at the moment, serves a gradua-- tion m2 on the'hand-wheel m1, embracing a height ofight of from 0 to 1000 meters, and an index k3 therefor is provided on the arm K1.

In what manner the abovev named curve lines z'l and 2 -are determined will now be explained with the assistance of the developed cylindrical surface of the drum J, see Fig. 5. It will then first be supposed, in order to determine the speed of flight during constant altitude of Hight, that the stop watch c1 in known manner is started at the moment, when the line of sight, which has previously been adjusted to a certain angle against the perpendicular, is directed against a certain point on the ground; and that, on following the point on the ground with the sight line, the stop watch is stopped at the instant, the line of sight becomes vertical. The distance which the flying machine has covered during the time indicated by the stop watch, the so called stop-time, is therefore the same as the altitude of Hight multiplied by the trigonometrical tangent of the originally setrangle between the line of sight and the perpendicular; and by dividing this distance by the stop-time, the speed of flight is obtained. For the sake of simplicity we will suppose that the originally set angle was The distance covered during the stop-time is in this case the same as the altitude of Hight, and the speed of flight is the altitude of Hight divided by the stop-time.

It has furthermore been supposed that the angle formed by the line of sight with a vertically adjustable line, in this case the axis of the rod g2, at the moment of ejection of the projectile, is considered as ejecting angle. Not taking into account such secondary influences as wind, height of barometer, etc., the ejecting angle depends onlv on two magnitudes, namely the altitude and speed of Hight. As now the speed is equal to the altitude of flight divided by the stop-time, the ejecting angle may therefore also be considered as a function of the altitude of flight and the stop-time.

The cylindrical surface of the drum J is thought bisected by that surface line 3 see- Fig. 5, which the index n.1 follows, when the axis of the rod g2 stands perpendicular, and the sight line, determined by the notch h3 and the point h1, is so adjusted, by turning the shaft F and the drum J, which is rigidly secured thereon, that the sight line becomes parallel with the axis of the rod g2. If the sight line is so adjusted, by turning shaft F, that the angle, which it forms with the axis of the rod g3 is equal to a certain ejecting angle (not zero), then the distance which the surface line 3 has been displaced relative to the index nl, measured circumf ferentially on the cylindrical surface of the drum J, 1s proportionate with the ejecting angle, provided, that the rod g2 retains its perpendicular position unaltered. From a Hxed Zero-point are now supposed to be laid out, in suitable scale on the surface line 3, the altitude of flight; and on a line 4, running through the zero-point of the surface line 3 in circumferential direction, are the menace ejecting angles to be similarly laid out in such a scale, that, on turning the drum J, the angle between the sight line and the axis of the rod g2 will be constantly equal to that ejecting angle, which is represented by the distance of the index n1 from the surface line 3, measured circumferentially. In Fig. 5 have been indicated along the surface line 3, the altitudes of Hight from 0 to 1000 meters at intervals of 100 meters; and along the circumferential line 4, the ejecting an-` gles from 0 to 60 degrees at intervals of 5 degrees. The relations between altitude of flight, the stop-time and the corresponding ejecting angle are now graphically illustrated in such a manner by the curves l in the cordinate system formed by the two axes 3 and 4, intersecting each other at right angles, that to each curve corresponds a constant value of the stop-time, and that the cordinates of each point on one of the curves represent the related values of the ejecting angle and the altitude of flight. If now the index nl is adjusted in axial direction to indicate a certain altitude of flight, and the drum J thereupon is turned until the mark n1 points to a curve which corresponds to the stop-time found out at this height of Hight, then the angle between the sight line and the axis of the rod g2 will be equal to the ejecting angle, which corresponds to the set altitude of Hight and the stop-time.

Each point of any curve chart 1 denotes a certain speed of flight. Supposing now, that all points of the curve chart 1, which correspond to. the same value of speed of Hight, are connected by one curve, and that a great number of such curves of different values of speed of Hight were scribed, a'

of the same curve express the two related values of the altitude of Hight and the eject ing angle. If now the drum J is so adjusted for a known speed of Hight, that'the mark n1, already adjusted in axial direction to indicate a certain altitude of Hight, will point to the curve corresponding to the speed of Hight, the angle between the sight line and the axis of the rod g3 is again equal to the corresponding eiecting angle.

In the curve chart 1, see Fig. 5, the individual curves are scribed fora stop-time ranging from 5 to 100 seconds; with the individual curves following each other at distances corresponding to every 5y second of stootime within the range of 5 to 50 seconds and of l0 seconds within the range of 50 to 100 seconds. The individual curves in the curve chart 2 are drawn for a range I of speed of'Hight of 10 vto 40 meter-seconds,

A 1 'the individual. curves following each other' in distances corresponding to every 5 meterseconds of speed 'of High In describing the use of the present sighting device, the wind inHuence, which in and falls in,n a plane,YV which n is laid vperpendicular through the target. In order now, underthese conditions, to determine the point fromiwhich the projectile should be thrown to hit a certain target, the index 'nl should Hrst be displaced, by means 'of the hand wheel m1, in the direction of the surface line a until the division line indicating for instance 500 meters altitude of Hight of the graduation m2 registers withl the index k3, while the Hying machine moves with uniform speed at constant altitude, which maybe readl 0H a barometer. For the purpose of determining the stop-time, the

sight line will now 'be so adjusted, by means.

of turning the shaft F, that itforms an V angle of with the perpendicularly situ seconds.

ated axis of the rod g2. 'At thc moment a certainpoint on the ground is visible in the sight line, adjusted as above indicated, the

stop watch c1 is startedv and again stopped' at that instant when the sight line, which' has been kept directed against the target,

arrivesin vertical position. YThe time read off the stop watch might for instance be 2O The drum J will then 'be turned by means of the hand wheel f1 until the index n1 points to the curve of the curve chart 1, which indicates a stop-time of 20 seconds. rlhe sight line then receives, by means of the gearing'fz, la, such an-inclinationrelative vtothe perpendicular axis of thejrod g2, that the angle of inclination will be equal to the ejectingangle, which corresponds to an altitude of Hight o f 500 metersand a stop-time of 20 seconds. If the Hying machine, after the reading'of the stop Watch, retains the same altitude, the

projectile must then bel thrown in known,

manner from. that point,.'from which the target is seen, when the sight line has been adjustedV as now described. Y)

'Should the Hying machine be compelled l,to change its altitude of Hight, afterthe reading of the stop watch, the sight line must be adjusted for a diHerent ejecting angle. It will, however, not be necessary to again determine the stop-time, as long as the, speed of Hight remains the same, because simultaneously with the determining of the stop-time to 20 seconds at the' original altitude of Hight of 500 meters, the speed of Hight was also determined and until the index nf again points to the curve of the curve chart 2, which corresponds to the speedof Hight of 25` meter-seconds, after having, by *turning the hand wheel m1, previously axially adjusted the index al to correspond to the new altitude of Hight.

As soon as this has been done the sight line has been adjusted, corresponding to the new altitude of Hight.

It will now be evident, that the described sighting device possesses the advantage in lits use, thatit is neither necessary to compute the speed of Hight from the altitude of Hight and the stop-time, nor to again determine` the'fstop-time for a change of altitude of Hight.

Without in` anyr manner changingr the' object of thepresent invention, the curve chart l might be exchanged for a curve chart, wherein each individual curve-corresponds to a constant altitude of Hight, and wherein one of the two cordinates of a curve point, measured in axial direction expresses the stop-time and the other'cordinate,meas ured in circumferential direction expresses the ejection angle.'I In this case, the curves of the same'speed of Hight must naturally also be changed, so that also here the coordinates of each curve point lexpress the -stop-time and the ejecting angle.

ing devices on air Ivehicles comprising a sight member, a reading-0H' means for indicating the angles of ejection of said projectile-ejecting device, said sight member being adjustable to correspond to the angles of ejection, 'said means having a mem ber provided with an index, a second member carrying two intersecting series of curves, one of said series of curves rep-resenting the relations between the height of Hight, the time necessary for traversing a horizontal distance proportionate to the height of Hight, and the angle of ejection in 'such a manner, that a constant value of the two -first-named magnitudes corresponds to each curve and that the cordinates of each curve. represent the angle of ejection and said third magnitude; the other of said series of curves comprising curves of equal speed of Hight, the Hrst-named member of thc :reading-0H'l means and said second memand consisting of a movable member and an index therefor; and a setting member f or said index for imparting transversal displacement of said index relative to the direction of movement of said movable member, the setting thus indicating altitude of Hight.

3. A sighting device for projectile-ejecting devices on air vehicles comprising a bracket, a revoluble shaft carried by the bracket, a pendulum hanging freely from said shaft and being provided With a circular guideway, the axis of which is parallel with said shaft axis, a sight bar having aiming members, said sight bar being mounted to run in said guideWay, a drum and a pinion rigidly secured on said shaft, teeth on said sight bar in mesh With said pinion, an index for said drum, said drum having a suitable scale for reading the angular movement of said drum and said sight bar, a screw spindle on Which said index is seated, said spindle having stationary bear' ings relative to said bracket, said spindle having a scale for indicating the axial displacement of said index relative said drum, the longitudinal axes of said drum and said spindle being parallel.

4. A sighting device for projectile-ejecting devices on air vehicles comprising a bracket, a revoluble shaft carried by the bracket, a pendulum hanging freely from said shaft and being provided With a circular guideway, the axis of which is parallel With said shaft axis, a sight bar having aiming members, said sight bar being mounted to run in said guideway, a drum and a pinion rigidly secured on said shaft, teeth on said sight bar in mesh with said pinion, an index forq said drum, said drum having a suitable scale for-reading the angular movement of said drum and said sight' bar, a screw spindle on which said index is seated, said spindle having stationary bearings relative to said bracket, said spindle having a scale for indicating the axial displacement of said index relative said drum.

the longitudinal'axes of said drum and saidspindle being parallel, said drum also being provided with a curve chart, each individual curve denoting a constant but different speed from its neighbor.

5. A sighting device for projectile-ejectbracket, a revoluble shaft carried by the bracket, a pendulum hanging freely from` said shaft and being provided With a circular guideWay, the axis of Which is parallel With said shaft axis, a sight bar having aiming members, said sight bar being mounted to run in said guideway, a drum and a pinion rigidly secured on said shaft, teeth on said sight bar in mesh with said pinion, an index for said drum, said drum" having a suitable scale for reading the angular bar movement of said drum and said sight bar, a screw spindle on Which said index is seated, said spindle having stationary bearings relative to said bracket, said spindle having a scale for indicating the axial displacement of said index relative said drum, the longitudinal axes of said drum and said spindle being parallel; said drum also being provided with a curve chart, each individual curve denoting a constant but different stop-time from its neighbor.

6. A sighting device for projectile-ejecting devices on air vehicles comprising a bracket, a revoluble shaft carried by the bracket, a pendulum hanging freely from said shaft and being pro-vdedwith al circular guideway, the, axis of which is parallel With said shaft axis, a sight bar having aiming members, said sight bari being mounted to run 'in said guideway, a drum and a pinion rigidly secured on said shaft, teeth on said sight bar in mesh With said pinion, an index for said drum, said drum having a suitable scale for reading the angular movement of said sight bar, a screvs7 spindle on which said index is seated, said spindle having stationary bearings relative to said bracket, said spindle having a scale for indicating the axial displacement of said,

index relative said drum, the longitudinal axes of said drum and said spindle being parallel, said drum being providedyvith a set of speed curves, each individual'curve denoting a constant, but fromfits neighbor different speed, and a set of stop-time curveseachI individual stop-time curve representing constant but from its neighbor different speed.I 1

7. A sighting device for projectile-eject.- ing devices onair vehicles comprising a bracket, a revoluble shaft carried by the bracket, a pendulum hanging freely from said shaft and being provided With a circular guideway the axis of which is parallel with said shaft axis, a sight bar having alming members, said sight bar being mounted to run in said guideWay,` a drum v and a pinion rigidly secured on said shaft,

teeth on said slght bar. in mesh with said pinion, an index for said drum, said drum having a suitable scale for readingthe angular movement of said sight'bar, a screw splndle on which said index is seated, said spindle having stationary bearings relative to said bracket, said spindle having a scale for indicating the axial displacement of said index relative said drum, the longitudinal axes of said drum and said spindle being parallel, said drum being provided with a set of speed curves, each individual curve denoting a constant, but from its neighbor different speed, and a set of stop-time curves, each individual stop-time curve representing constant but from its neighbor diierent speed; said angular scale .repredisplacement scale representing the altitude 15 of aight.

The foregoing specification signed at Bari men, Germany, this 26th day of November, 1913.

OTTO RITTER YoN EBERHARD.

In presence of- ALBERT NUFER, FRANCES NUTER. 

